/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.transforms;



import com.bff.gaia.unified.sdk.values.KV;

import com.bff.gaia.unified.sdk.values.PCollection;

import com.bff.gaia.unified.sdk.values.TimestampedValue;



/**

 * {@link PTransform PTransforms} for reifying the timestamp of values and reemitting the original

 * value with the original timestamp.

 *

 * @deprecated Use {@link Reify}

 */

@Deprecated

class ReifyTimestamps {

  private ReifyTimestamps() {}



  /**

   * Create a {@link PTransform} that will output all input {@link KV KVs} with the timestamp inside

   * the value.

   *

   * @deprecated Use {@link Reify#timestampsInValue()}

   */

  @Deprecated

  public static <K, V>

      PTransform<PCollection<? extends KV<K, V>>, PCollection<KV<K, TimestampedValue<V>>>>

          inValues() {

    return new InValues<>();

  }



  /**

   * Create a {@link PTransform} that consumes {@link KV KVs} with a {@link TimestampedValue} as the

   * value, and outputs the {@link KV} of the input key and value at the timestamp specified by the

   * {@link TimestampedValue}.

   *

   * @deprecated Use {@link Reify#extractTimestampsFromValues()}.

   */

  @Deprecated

  public static <K, V>

      PTransform<PCollection<? extends KV<K, TimestampedValue<V>>>, PCollection<KV<K, V>>>

          extractFromValues() {

    return new ExtractTimestampsFromValues<>();

  }



  private static class RemoveWildcard<T>

      extends PTransform<PCollection<? extends T>, PCollection<T>> {

    @Override

    public PCollection<T> expand(PCollection<? extends T> input) {

      return input.apply(

          ParDo.of(

              new DoFn<T, T>() {

                @ProcessElement

                public void process(@Element T element, OutputReceiver<T> r) {

                  r.output(element);

                }

              }));

    }

  }



  private static class InValues<K, V>

      extends PTransform<PCollection<? extends KV<K, V>>, PCollection<KV<K, TimestampedValue<V>>>> {

    @Override

    public PCollection<KV<K, TimestampedValue<V>>> expand(PCollection<? extends KV<K, V>> input) {

      return input.apply(new RemoveWildcard<KV<K, V>>()).apply(Reify.timestampsInValue());

    }

  }



  private static class ExtractTimestampsFromValues<K, V>

      extends PTransform<PCollection<? extends KV<K, TimestampedValue<V>>>, PCollection<KV<K, V>>> {

    @Override

    public PCollection<KV<K, V>> expand(PCollection<? extends KV<K, TimestampedValue<V>>> input) {

      return input

          .apply(new RemoveWildcard<KV<K, TimestampedValue<V>>>())

          .apply(Reify.extractTimestampsFromValues());

    }

  }

}